The factor most crucial in determining the effectiveness of the matching procedure for developing ...

The factor most crucial in determining the effectiveness of the matching procedure for developing equivalent groups is whether
 
  a. the matching variable is significantly related to the study's dependent variable.
  b. the matching variables were assigned to both groups.
  c. the sample is random and representative of the larger population.
  d. the study is causal-comparative or experimental.

Ques. 2

In the fall semester, a professor compared a lecture approach to teaching statistics (using a sophomore class) with a problem-oriented approach (using a senior class). Both sections were given the same final exam. The professor repeated the same experiment in the spring semester. This study shows a confounding of
 
  a. test scores with teaching approaches.
  b. class levels with test scores.
  c. teaching approaches with class level.
  d. semester with teaching approaches.

Ques. 3

Selection bias is a threat to internal validity arising from failure to use
 
  a. a control group. c. reliable measuring instruments.
  b. counterbalancing across conditions. d. random assignment.

Ques. 4

If a researcher compared left-handed versus right-handed girls on a reading test after giving half of them special training, then the attribute variable and one likely extraneous variable, would be respectively
 
  a. special training; reading scores.
  b. handedness; age of student.
  c. reading scores; ability level.
  d. special training; gender.
  e. handedness; special training.